Tobacco smoke filter material



Dec. 19, 1961 M s. BLOCK TOBACCO SMOKE FILTER MATERIAL Filed Sept. 18, 1957 T? 1 I l I a c") "a F) I c JR Q Eoom wz .1042 025.42 II INVENTOR: "M" SABEL BLOCK A T TORNEYS.

United States Patent Office V 3,013,891 Patented Dec. 19, 1961 3 013 891 TOBACCO sMorZE a rman MATERIAL M Sabel Block, Bloomfield, N.J., assignor to P. Lorillard Fompany, New York, N.Y., a corporation of New ersey Filed Sept. 18, 1957, Ser. No. 684,773 Claims. (Cl. 117-19) terial, and then forming a bundle of such coated filaments into a tobacco smoke filter for incorporation into a cigarrette. However, the distribution of the fine material on the filaments is not uniform, since the material tends to coagulate into pellets and large areas of the filament are left uncoated. Accordingly, cigarette filters formed of this material will not be uniform, and some filters contain large pellets of flock which often grow to diameters up to about one thirty-second of an inch and sometimes are visible at the tip of the filter. Thus, whereas the weight of the filter may conform to the desired weight of a uniformly distributed filter, the flock may be non-uniformly distributed and be segregated in the form of large pellets scattered through the filter, thereby rendering the filter material non-uniform and impairing its filtering action and draw.

The present invention has for its object the provision of a method and apparatus for producing a superior tobacco smoke filter material continuously in quantity, which is particularly adaptable for incorporation with cigarettes during the manufacture of the latter by commercially practicable methods without materially increasing the cost of the cigarettes, and which will permit the cigarette to draw naturally and produce no noticeable effect on the senses of the user.

In accordance with the invention, the tacky filaments after being coated with the fine material in the aforementioned known manner are vibrated to more evenly distribute the fine material thereon, including the breakup of at least some of the coagulated pellets and the redistribution of the particles thereof, and then passing the filaments over successive rollers spaced transversely apart so as to flex and reflex the filaments to release any surplus pellets which fall therefrom 'by gravity. Accordingly, the filaments have the fine material evenly distributed thereon so that when gathered and formed into a cigarette filter the filters are uniform in composition and draw.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to the apparatus and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description of a preferred embodiment thereof, when read in connection with the accompanying drawing which illustrates the apparatus of this invention whereby the various successive steps in the process of the invention may be carried out.

Referring to the drawing, numeral 10 designates a flat ribbon or band formed by the generally parallel assembly of discrete filaments of natural or synthetic material, preferably crimped synthetic cellulose acetate filaments of a diameter range on the order of about 2 to 8 denier (14 to 29 microns) of the general type described in Crawford and Stevens Patent No. 2,794,239, granted June 4, 1957,

or equivalent filamentary materials such as these described in copending application Serial No. 654,701, filed April 24, 1957, by Harris B. Parmele. While the filtering medium is represented as a ribbon or band of discrete, generally parallel filaments, they may be felted to a degree or loosely woven, but not closely so as to afford spaces between the adjacent filaments.

The ribbon or band of filaments 10 is passed by driven feed rolls 11 and 12 through a spray booth 13 wherein spray nozzles 13' apply an adhesive or plasticizer from above and below the ribbon or band 10 in the manner disclosed in Crawford and Stevens Patent No. 2,794,480. The filaments which compose the 'band or ribbon 10 are first spread apart by elastic surfaced driven feed rolls 11 and 12 or by an air blast so that the surface of each filament is exposed for even coating with the adhesive or plasticizer to render its surface tacky.

A plasticizer is preferred since it does not increase the diameter of the filament as does an adhesive and the amount is, for example, on the order of about 25% by weight of the'filament. A preferred plasticizer is glycerine triacetate triacetin, although any other adhesive orplasticizer, such as dibutyl phthalate, triethyl citrate and the like, having the same or similar properties of rendering the filaments temporarily tacky and subsequently drying without leaving an objectionable odor or impairing the flavor of the smoke passing through the finished filter will serve the purpose. Where an adhesive is used it may be a solution of cellulose acetate.

From the spray booth 13 the ribbon or band 10 passes through a cloud chamber 14, such as is disclosed in Taylor Patent No. 2,034,008, in which finely-divided material is dispersed as a cloud in a known manner and the particles are thereby adhered to the tacky filaments of ribbon or band 10. Alpha cellulose flock is a suitable material, the particles of which are essentially fine fiber of approximately 35-60 microns in length and on the order of about 2-10 microns in diameter. Equivalent materials having similar properties and diameters on the order of those of tobacco smoke particles (0.1-2.0 microns) may be used with equal facility, such as the natural and synthetic fibers disclosed in Knudsen Patent No. 2,761,798 and said Parmele application. The fibers are suspended in the aeriform current within cloud chamber 14 and are thus agitated and whirled about to collect on the tacky surfaces of the filaments of the ribbon or band 10 passing through the chamber. The aeriform current is produced by blowing air, or other gaseous medium, into a cloud chamber 14 by at least one, and preferably two, fans 15.

As previously stated, the distribution and adhesion of the flock fibers on the filaments of ribbon or band 10 in the cloud chamber 14, however, is not uniform. Frequently, the flock fibers coagulate in pellets on the top and bottom surfaces of the filaments passing through the cloud chamber, and extensive areas of the filament surfaces remain uncoated altogether, with the result that filters made therefrom are not uniform in construction and draw, and often contain visible pellets.

To overcome this disadvantage, in accordance with the present invention, the ribbon or band 10 passes from the cloud chamber 14 through a vibrator 16 such as a model V-30 Syntron electrical vibrator, to more uniformly distribute the unadhered flock fibers and cause them to fall between and against the tacky filaments and adhere thereto. The vibration also shakes off or breaks up the coagulated pellets for redistribution of individual fibers on the uncoated surfaces of the filaments. However, not all of the pellets will be dislodged or broken up by vibration alone.

It has been found that the remaining pellets have been loosened or freed from the filaments of ribbon or band 10 by the vibration, so that they maybe dislodged therefrom I by flexure and gravity. Accordingly, the filaments are flexed in one direction by passing the ribbon or band 10 over roller 17, whereby those pellets remaining on the under surface thereof are dislodged and fall off by gravity. Then the ribbon or band 10 is passed in a substantially vertical direction, preferably rearwardly inclined to the vertical, about a roller 18 positioned above and to the right of roller 17 as seen in the drawing.

As the ribbon 10 moves vertically, it is reflexed again in a curved pass in the opposite direction as it moves over roller 18, so that the remaining flock pellets are loosened and fall off, while the individual flock particles adhering to the filaments remain unaffected. If desired, a pair of oscillating rods forming a vibrator or knocker 20 may be applied against the ribbon or band 10 during its substantially vertical pass between rollers 17 and 18 to agitate the same and thus aid in eliminating loose agglomerates or pellets. In this manner, virtually all pellets (99 plus percent) are removed. It has been found that the vibrator 16 is more than 95% effective in breaking up pellets and redistributing the flock particles or fibers, whereas the reverse flexing, second vibration and vertical movement of the ribbon or band 10 is effective in ejecting coagulated pellets. The pellets or particles dislodged from the ribbon 10 by the vibrator 20 and by flexing the ribbon over the roller 18 are deflected by a deflector 21 into a collector 22 so that they do not fall back on the ribbon. Also, as indicated in the drawings, the ribbon can be further flexed and supplied to the feed end 19 of a filter plug making machine by means of rollers 23 and 24 which are also provided with collectors 25 and 26 for any dislodged fibers.

The fine flock fibers are adhered to the filaments in random but substantially uniformly spaced relation, i.e., a few lie flat against the filament surface in lengthwise relation, but the majority of them stand on end and resemble hairs or extend diagonally. Accordingly, when the filaments are arranged longitudinally in a bundle, the laterally projecting fibers adhered thereto extend into and constitute obstructions in the passages between the filaments, which obstructions interrupt the fiow of tar, nicotine and other particles in tobacco smoke so as to deflect them out of the stream in the manner described in said Knudson patent and Parmele application.

Having thus formed a filter material in which the fine flock fibers are distributed uniformly over and throughout the filaments and which is virtually entirely free from pellets of coagulated flock fibers, the ribbon or band 10 passes to the feed end 19 of any suitable machine for gathering the filaments comprising ribbon or band 10 into a suitable roving for forming the same into filter plugs. United States Patent No. 2,793,572 illustrates a machine which is suitable for making the filter plugs.

The invention has been shown by way of example only, and many modifications and variations may be made therein without departing from the spirit of the invention. Therefore, it is understood that the invention is not to be limited to any specified form or embodiment except insofar as such limitations are set forth in the appended claims.

I claim:

1. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament, which comprises agitating the filament to redistribute the ccnglomerated and unadhered particles on the uncoated tacky surface of said filament, simultaneously bodily moving said filament to said the said particle redistribution, whereby the filament is substantially uniformly coated with the particles, then moving said filament substantially vertically to remove any unadhered particles by gravity, and defiecting the unadhered particles away from the filament.

2. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surfaces of a plurality of elongated filaments arranged in substantially parallel relation as a band, which comprises agitating the band of filaments to redistribute the conglomera-ted and unadhered particles on the uncoated tacky surface of said filaments, simultaneously bodily moving said band of filaments to aid the said particle redistribution, whereby the filaments are substantially uniformly coated with the particles, then moving said band of filaments substantially vertically to remove any unadhered particles by gravity, and deflecting the unadhered particles away from said band of filaments.

3. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament, which comprises agitating the filament to redistribute the conglomerated and unadhered particles on the uncoated tacky surface of said filament, simultaneously bodily moving said filament to aid the said particle redistribution, whereby the filament is substantially uniformly coated with the particles, flexing said filament transversely to dislodge unadhered particles therefrom, then moving said filament substantially vertically to remove any unadhered particles by gravity, and deflecting said unadhered particles away from said filament.

4. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament, which comprises agitating the filament to redistribute the conglomerated and unadhered particles on the uncoated tacky surface of said filament, simultaneously bodily moving said fila- 30 ment to aid the said particle redistribution, whereby the filament is substantially uniformly coated with the particles, moving said filament substantially vertically to remove any unadhered particles by gravity, again agitating said filament while moving in said substantially vertical direction to dislodge loose particles therefrom,

and deflecting said loose particles away from said filament.

5. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surfaces of a plurality of elongated filaments arranged in substantially parallel relation as a band, which comprises agitating the band of filaments to redistribute the conglomerated and unadhered particles on the uncoated tacky surface of said filaments, simultaneously bodily moving said band of filaments to aid the said particle redistribution, whereby the filaments are substantially uniformly coated with the particles, moving said band of filaments substantially vertically to remove any unadhered particles by gravity, again agitating said band of filaments while moving in said substantially vertical direction to dislodge loose particles therefrom, and defiecting said loose particles away from said band of filaments.

6. A method of uniformly distributing finely-divided short fibers deposited non-uniformly as a coating on the tacky surfaces of a plurality of elongated filaments arranged in substantially parallel relation as a band, which -comprises agitating the band of filaments to redistribute the conglomerated and unadhered short fibers on the uncoated tacky surface of said filaments, simultaneously bodily moving said band of filaments to aid the said short fiber redistribution, whereby the filaments are substantially uniformly coated with the short fibers arranged at indiscriminate angles thereto, moving said band of filaments substantially vertically to remove any unadhered short fibers by gravity, again agitating said band of filaments while moving in said substantially vertical direction to dislodge loose particles therefrom, and deflecting said loose particles away from said band of filaments.

7. A method of uniformly distributing finely-divided particles deposited non-uniformly as a coating on the tacky surfaces of a plurality of elongated filaments arranged in substantially parallel relation as a band, which comprises spreading the adjacent filaments laterally out of contact with each other, agitating the band of filaments to redistribute the conglomerated and unadhered particles on the uncoated tacky surface of said filaments, and simultaneously bodily moving said band of filaments to aid the said particle redistribution, whereby the filaments are substantially uniformly coated with the particles.

8. Apparatus for uniformly distributing finely divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament, the combination of means for driving said filament substantially horizontally, a vibrator for agitating said filament transversely to redistribute agglomerated and loose particles on uncoa-ted areas of said filament, first means for deflecting said filament from said substantially horizontal to a substantially vertical direction so that said filament is flexed to remove unadhered particles by gravity, deflector means positioned adjacent said filament at the point where said filament moves in a substantially vertical direction, second means for deflecting said filament from said substantially vertical direction back to a substantially horizontal diree, tion to further flex said filament, and first and second means to collect the removed, unadhered particles adjacent said first and second deflecting means, respectively, so that the unadhered particles are prevented from coming into contact with said filament after they are removed. 9. Ap aratus for uniformly distributing finely divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament as set forth in claim 8, including a second vibrator to vibrate said filament as it passes in said substantially vertical direction.

10. Apparatus for uniformly distributing finely divided particles deposited non-uniformly as a coating on the tacky surface of an elongated filament as set forth in claim 8, including third means for deflecting said filament after said second deflecting means to flex said filament transversely to an angle at least ninety degrees with the horizontal, and third means for collecting the unadhered particles adjacent said third deflecting means.

References Cited in the file of this patent UNITED STATES PATENTS 296,428 McMillen et al Apr. 8, 1884 2,034,008 Taylor Mar. 17, 1936 2,340,897 Pierson Feb. 8, 1944 2,371,605 Carlton et a1 Mar. 20, 1945 2,603,575 Schramm July 15, 1952 2,655,895 Abeles Oct. 20, 1953 2,774,680 Hackney et al Dec. 18, 1956 FOREIGN PATENTS 312,412 Great Britain May 30, 1929' 

1. A METHOD OF UNIFORMLY DISTRIBUTING FINELY-DIVIDED PARTICLES DEPOSITED NON-UNFORMLY AS A COATING ON THE TACKY SURFACE OF AN ELONGATED FILAMENT, WHICH COMPRISES AGITATING THE FILAMENT TO REDISTRIBUTE THE CONGLOMERATED AND UNADHERED PARTICLES ON THE UNCOATED TACKY SURFACE OF SAID FILAMENT, SIMULTANEOUSLY BODILY MOVING SAID FILAMENT TO SAID THE SAID PARTICLE REDISTRIBUTION, WHEREBY THE FILAMENT IS SUBSTANTIALLY UNOFORMLY COATED WITH THE PARTICLES, THEN MOVING SAID FILAMENT SUBSTANTIALLY VERTICALLY TO REMOVE ANY UNADHERED PARTICLES BY GRAVITY, AND DEFLECTING THE UNADHERED PARTICLES AWAY FROM THE FILAMENT. 